Is there anyplace I can get more detailed specs on the RC, specifically the antenna's used... I see specs on page 61 of the manual but I am looking for something a litlte more detailed


Thanks

30 views no replies,  guessing dji did not publish anything on the controller... humm

No, they did not. You might be able to get a response if you provide more details on exactly what you're trying to do.

The info in the manual is the info given.
If you are looking for antenna specifics, I don't believe DJI offers that kind of info.

Thanks ken.. being a former RC plane pilot and a HAM operator, I was hoping to gain some insight as to transmitter output in watts, antenna gain if any, etc....

Thanks again

Warnberg Posted at 2016-9-22 12:27
Thanks ken.. being a former RC plane pilot and a HAM operator, I was hoping to gain some insight as  ...

Are you trying to increase the p4's range?

Roughly:

The RC is putting out about 15dBm (35 milliwatts).
The P4 is putting out about 29 - 30 dBm (700 - 800 milliwatts).

Keep in mind the P4 is turning all over the place, so it's signal strength at the RC  varies as it gets bounced all over.
I think they use the left side antennas for the Video, so if you start losing signal, turn left!

I'm am looking into tinkering with some 2.4GHz antannas I have that are more directional, provide some gain and are much cheaper options then what I see currently on the market.

Warnberg Posted at 2016-9-22 10:01
I'm am looking into tinkering with some 2.4GHz antannas I have that are more directional, provide so ...

If you are talking about adding an active (dc voltage) amplifier, I would not do that:

IMO:
Unless you have a MIL STD amplifier with harmonic and spurious levels cut down to -60 dBm, these will introduce noise, and noise is a major enemy for the P4.  It uses very advanced algorithms to extract the control signals from very low RF signals, so any additional noise will counter any signal gain.

DC power supplies also add low frequency noise

Another consideration is that active devices tend to fail a lot more often than passive antenna mods.  What if you were flying beyond the safe RTH distance, and then you dc supply fails, then you lost your P4.

The passive antenna mods out there do work.  They re-distribute the energy in the FWD direction, and even though they do not increase the signal power, they in essense do, increase the range by directing the energy in a narrower beam.

Have you tried the simple parabolic boosters, which mount on the stock antennas?  Those will offer about 50% - 100% range increase. That may be a good starting point to see if the issue you are having is signal strength.

Not planning on any booster or amplifier .. a simple directional antenna is more efficient then an omni directional with a parabolic adapter. ... bouncing a signal you loose strength, a focused beam is much more effective.  Gain can be achieved without boosters or amplifier of any kind... look up yagi type antennas

Thanks
After looking around more I see the Transmitted power (EIRP) is FCC:23dBm, which means we are talking milliwatts of output power here:  


So again, a focused trasmitted signal as well as a focused reveiver would be much more efficient...

MD_Icarus Posted at 2016-9-22 21:38
Roughly:

The RC is putting out about 15dBm (35 milliwatts).

I see you found some info, there's lots of forums out there that have tons of info.
Lookup IBCRAZY, Alex is pretty much the master of that stuff that I know of.

BONJOUR QUI PEUT me donner un renseignement j'ai plus de liaison entre la RC et le drome sans savoir pourquoi???

MD_Icarus Posted at 2016-9-22 22:14
If you are talking about adding an active (dc voltage) amplifier, I would not do that:

IMO:

I have tried a parabolic booster but saw no better range than without them.  If you have a pair that work as claimed, please post the link.  I hate to buy another pair to experiment with.   I'm thinking about going with the MaxxRange panel since the parabolics didn't work for me.  

Tell you the truth, I had the best experience with 2 CDs taped to the antenna.

If I could get a reliable 50-100% increase in range I would be ecstatic.

raphael7369 Posted at 2016-9-22 18:37
BONJOUR QUI PEUT me donner un renseignement j'ai plus de liaison entre la RC et le drome sans savoir ...

I do not understand...

https://www.amazon.com/Bestmaple ... 32QF2WS2K94YQGXGKR1
These gave me about 70% increase in range.

But there are so many variables, having different tolerances, thus my results may not match yours!

One preliminary result I am evaluating using 2 antenna mods (I only did 2 tests on this today, and I am in a new area so I do not know if there is interference from some RF source in the area) is that the P4 video transmission signal weakens drastically once the P4 turns right. Just making a right turn resulted in signal level dropping to 21% from 100% using both mods.  
I plan to fly in the same area soon having the P4 flying straight and making a left turn...

Warnberg Posted at 2016-9-22 16:08
Not planning on any booster or amplifier .. a simple directional antenna is more efficient then an o ...

In simple terms, it may be easier to just consider RMS voltage:

In a 50 OHM circuit,
The RC is putting out a little over 1 volt of signal.  The P4 is putting out about 5 - 6 volts of signal. Let's not forget that we do not want too much RF energy close to us!  I used to work with a lot higher frequencies in the 20 - 30 GHZ range and even though the power was always below -10 dBm, my 2 fingers which touched the connectors would get white and scaly! Even though the frequency here is much lower, you still do not want a super active amplifier around or below your waist!

For reference purposes: Our microwaves work at the same frequency range, but they output about 700 Watts of RF power. Thats about 700 times the RC power. And yes, I and my family stay away from it when it's on!  If you put a meter just next to it, you will get a low reading.

I hope this does not come off as being an azz and if it does I apologize ahead of time.

1) you are making an assumption that I want to modify and keep the antenna on the remote (not the case)
2) I have no idea what you mean by "volts of signal" this is no term I've ever heard

I would rather not divulge what I'm thinking and going to test at this time until I have had time to sort out the numbers and design.

Thanks

Warnberg Posted at 2016-9-23 08:18
I hope this does not come off as being an azz and if it does I apologize ahead of time.

1) you are  ...

I thought that most people who do not have an engineering background may understand the term Volts better than dBm, dBi, dBc, mW....etc.

Our signal is a sine wave, which has a peak voltage. This is similar to our electricity sine wave, but that is at very low frequency of 60 HZ.  The peak voltage is about 170 Volts, but the RMS voltage (average) is 120 Volts. So if I use a meter which is derived from calculating heat, it reads 120 volts.  But if I place an oscilloscope it shows 170 Volt peaks.

Yes, I do understand... HAM operator (Extra Class), and former Electrical Engineer..  Thanks
Think of a remote mounted 16 Element and 15 dBi Gain 2.5 GHz antenna mounted on a tripod pointed in the direction you want to fly... as an example

I am not trying to "be the rain in your parade", BUT

Even though I have a lot of RF Design experience with antennas, one thing I believe is not to try to re-invent if there is a proven design out there. There are so many factors to consider like SWR, gain mismatch, relative antenna placement, Polarization characteristics (V, VH, degrees of offset,...........)  Unless you have very expensive test equipment, (scalar network analyzer, reference antennas, shielded test room...) there is no way of proving such a design.

But let's not forget another important aspect:

Unless you boost the P4 antennas too, then it won't matter what you do on the ground; You will lose signal from the P4 anyway.
Even if you use the following set up, which I called previously the ULTIMATE BOOSTER!!!

Take a look at this.. drone defender

what does that look like???  looks like a directional 2.4 GHz antenna to me.. if it can be used to interfear with the signal why couldn't one be used to enhance the signal?  BOTH send and receive?

When you want to hear something better what do you do?  cup your ear to focus the direction you are listening... same principal applies here.. directional antenna means you listen and send the signal in a focused direction...

Warnberg Posted at 2016-9-23 20:39
Yes, I do understand... HAM operator (Extra Class), and former Electrical Engineer..  Thanks
Think o ...

You might try searching in the long distance FPV flying of RC planes for similar setups to what you are describing.   The problem seemed to be the tracking mechanism used to keep the narrow focus beam of antenna pointed correctly.

EdM Posted at 2016-9-24 09:06
You might try searching in the long distance FPV flying of RC planes for similar setups to what yo ...

Yes.. it will all depend on the antenna gain.. higher the gain the narrower the "cone".. example (this is a rough estimate/guess)  a 25 dbi gain antenna may have a 25 degree vertical and horizontal field, where as a 15 dbi gain may have a 40 degree field.  So obviously you would want to keep the drone in that cone..